The present invention relates to an actuator having up to two actuating arms and an enclosed compensator, and which is driven by a piezo or other smart material device. Actuators according to the present invention may be adapted for use as an actuator, an energy capture device, or a sensor.
Smart material actuators are known in the art. However, such actuators typically have an open compensator surrounding the piezo or other smart material device. Open compensators have been thought to be preferred because of ease of assembly. A significant limitation of such configurations, however, is that the piezo or other smart material device remains exposed. The present invention overcomes such limitations by providing an actuator with up to two arms in which the piezo or smart material device remains protected, and which remains convenient to assemble.
A further objective of the present invention is to provide an actuator apparatus capable of operation at high frequencies. Known smart material actuators tend to fail when operated at very high frequencies of repeated activation and deactivation. One reason for such failures is that the actuating arms tend to overextend during high speed operation and especially when operating at resonant frequencies. Certain embodiments of the actuator of the present invention, however, are designed to overcome such limitations both by reducing the weight of the actuating arms and by providing dampeners adapted to prevent such overextensions without hindering high speed operation. The result is an actuator capable of operation at very high frequencies.
A still further objective of the present invention is to provide a smart material actuator capable of being operated with actuating arms at a variety of angles. Allowing use of actuating arms of varying angles allows for greater flexibility as arm angles can be selected to meet physical constraints imposed by differing applications. At the same time, it is disclosed that certain ranges of arm angles result in more efficient operation than others in terms of actuator work output. Accordingly, by providing an actuator apparatus capable of use with multiple arm angles, it becomes possible to optimize efficiency by adjusting arm angles.
In addition, the present invention is adapted such that common components can be utilized to assemble actuators of several configurations. This allows for flexibility and efficiency in manufacturing, as common components may be manufactured in bulk and then assembled in wide range of configurations adapted to different applications.